Gasket for electric equipment



March 7, 1961 w. KES ETAL 2,974,183

GASKET FOR ELECTRIC EQUIPMENT Original Filed April 21, 1954 Fl(5.2b

FIG]:

United States Patent GASKET FOR ELECTRIC EQUIPMENT Continuation ofapplication Scr. No. 424,565, Apr. 21, 1954. This application Apr. 8,1959, Ser. Ne. 805,093

4 Claims. (Cl. 17435) This invention relates to a gasket for electricequipment suitable as a moisture seal and electric seal between edges ofa hollow shield for electric equipment.

This application is a continuation of application Serial No. 424,565,filed April 21, 1954, now abandoned.

it has heretofore been extremely difficult to provide a satisfactoryelectric seal and moisture seal between edges of the housing of, forexample, radar equipment capable of shielding the internal electriccircuits of the equipment from external electric fields and capable ofpreventing damage to the circuits due to moisture leakage.

It is an object of the invention, therefore, to provide a gasket of thetype described which is capable of providing a suitable electric ormoisture seal or both.

In accordance with the invention, a sealed joint in an electrical shieldwhich completely encloses and thereby electrically shields electricequipment against electric fields comprises juxtaposed edges in theshield forming a line of closure therein and a flat gasket strip ofresilient material between the edges. The invention also includes alength of metal braid permanently aflixed to the gasket strip along anedge thereof in electrical contact with the edges of the shield alongthe line of closure.

For a better understanding of the present invention, together wtih otherand further objects thereof, reference is had to the followingdescription taken in connection with the accompanying drawing, and itsscope will be pointed out in the appended claims.

Referring to the drawing:

Fig. 1 is an illustration of a housing or shield for electric equipmentsuch as radar equipment;

Fig. 2a is a top view of a gasket constructed in accordance with theinvention;

Fig. 2b is a cross section of the Fig. 2a gasket; and

Fig. 3 is a cross section showing the positioning of the Fig. 2b gasketin the Fig. 1 shield.

Referring now to Fig. 1., an electrical shield there represented forcompletely enclosing and thereby electrically shielding electricequipment against electric fields has a removable cover 11 which may beaffixed by' any suitable means (not shown) to edges 12, 12, 12, 12 ofthe shield 10 to shield the electric equipment. The juxtaposed edges ofthe shield 10 and its cover 11 form a line of closure along which theremay be disposed a flat gasket strip 13 of resilient material of, forexample, rubber, represented in Figs, 2a and 2b. A compressible metaltape 14 preferably comprising compressible rolled metal braid isimbedded in and supported by the rubber strip 13 along an edge thereofby any suitable means, such as vulcanizing or molding or by splittingthe edge of the Patented Mar. 7, 1961 'ice rubber strip and cementingthe tape within the rubber strip between the split faces thereof.

Fig. 3 shows how the gasket constructed in accordance with the presentinvention may be positioned between the shield 10 and its cover 11.

The braid 14 is so imbedded in the gasket that the main body of thebraid is in electrical contact with the shield along the line of closureto bar electric fields from the space therein. Accordingly, the rubberstrip acts as a moisture seal while the metal braid acts as an electricseal. Because of the edgewise relation between the rubber strip and themetal braid, both may be firmly clamped between the juxtaposed edges ofthe shield 10, 11 of Fig. l to form a unitary effective electric andmoisture seal.

While there has been described what is at present considered to be thepreferred embodiment of this invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention, and it is, therefore,aimed to cover all such changes and modifications as fall within thetrue spirit and scope of the invention.

What is claimed is:

l. A sealed joint in an electrical shield which completely encloses andthereby electrically shields electric equipment against electric fieldscomprising: juxtaposed edges in the shield forming a line of closuretherein; a fiat gasket strip of resilient material between the edges;and a length of metal braid permanently affixed to the gasket stripalong an edge thereof in electrical contact with the edges of the shieldalong the line of closure.

2. A sealed joint in an electrical shield which completely encloses andthereby electrically shields electric equipment against electric fieldsand moisture leakage comprising: juxtaposed edges in the shield forminga line of closure therein; a flat gasket strip of resilient materialbetween the edges for preventing moisture leakage; and a length of metalbraid imbedded in the gasket along an edge thereof in electrical contactwith the edges of the shield along the line of closure to bar externalelectric fields from the space between them.

3. A gasket for electrically shielding electric equipment comprising: aflat strip of supporting material having a length of rolled metal braidpermanently afiixed along an edge thereof for electrically shieldingsaid electric equipment.

4. A gasket for electrically shielding and moisture-sealing electricequipment comprising: an elongated flat strip of rubber-like materialfor moisture-sealing said electric equipment having roller metal braidimbedded therein along an edge thereof for electrically shielding saidelectric equipment.

References Cited in the file of this patent UNITED STATES PATENTS741,808 Miner Oct. 20, 1903 2,454,567 Pierson, Ir. Nov. 23, 19482,783,295 Ewing Feb. 26, 1957 FOREIGN PATENTS 487,463 Great Britain June21, 1938 OTHER REFERENCES Hall: Abstract of application Serial Number616,923, published March 18, 1952, 656 O.G. 884.

